US2250179A - Gun sight - Google Patents

Description

33-2600 OR 29.25%179 SR Search Room July 22, 1941. BROWN 2,250,179

GUN S IGHT Filed Aug. 29, 1940 Q .3 FIG. 5.

ATTORNEY.

33. GEOWIETRICAL 1N8 l HUlVltNlts.

Patented July 22, 1941 UNITED STATES Search PATENT OFFICE 4 Claims.

My invention relates to a new and improved gun sight, which is intended for use in connection with rifles, machine guns, etc.

One of the objects of the invention is to provide an adjustable sight whereby the marksman can regulate the elevation of the gun immediately, automatically and substantially correctly, in accordance with the trajectory of the ammunition which is being used.

Another object of my invention is to provide a gun sight which is turnable relative to a predetermined axis, in order to permit said regulatlon of the elevation of the gun, so that the adjusted sight can be used for firing at targets of different sizes, while using ammunition which has the same trajectory. This predetermined axis, around which the sight is turned or tilted, is preferably normal to the axis of the barrel. predetermined axis may be horizontal or qvertical, when the axis of the barrel is horizontal. The sight can also be adjusted for use on respective different guns, which use bullets or the like which have respective different trajectories.

Other objects of this invention are stated in my application Serial No. 335,877, filed in the U. S. Patent Office on May 18, 1940, of which this application is a continuation-in-part, reference being made to the disclosure of said application with the same force and effect as if repeated herein.

Fig. 1 illustrates one embodiment of the invention.

Fig. 2 is a front elevation of Fig. 1.

Fig. 3 is a top plan view of the second embodiment of my invention, on the line 3-3 of Fig. 4.

Fig. 4 is a front elevation of Fig. 3.

Fig. 5 diagrammatically illustrates a practical example in calculating the curves of the legs of the sight, as later stated herein.

The improved sight can be used as the front sight of a gun or rifle, in order to replace the conventional iron sight. In such case the rear sight should be a peep sight. The peep sight is well-known per se so that it is not illustrated in the drawing. The peep sight has a small opening, in order to show the front sight more clearly, while the eye of the marksman is focussed on the target.

Figs. 1 and 2 show a gun barrel l, which has the bore 2. The barrel I is provided with a conventional dovetail slot, in which the corresponding supporting block 3 of the improved sight is located. The block 3 is held in said slot in any suitable manner. The improved sight is mounted in a frame 4, which is suitably connected to the block 3. In the embodiment shown in Figs. 1 and 2, the improved sight 5 has the upper or outer ends of its legs mounted in bearings 6 and I, so that the sight 5 is turnable or tiltable relative to an axis of turning which may be designated as a horizontal axis. This axis is perpendicular to the axis of the bore 2, and it is horizontal when the axis of the barrel is horizontal. The frame 4 has an axis which is parallel to the axis of the bore 2. The bearings 6 and I are Room suitably connected to the frame 4. The sight 5 i is turned relative to said horizontal axis by means of a hand wheel or head 8. Any suitable conventional means (not shown) may be provided for holding the sight 5 releasably in its adjusted position. Such means may comprise an ordinary friction washer or the like. One of the outer faces of the frame 8 is provided with a scale 9 and the turnable head has a suitable index for cooperating with said scale.

The sight 5 can be made of thin wire or of thin strip metal which is stamped out by a cutting die into the shape shown in detail in Fig. 5, so that the sight can be stamped out of a thin sheet of metal. Theoretically, and as shown in Fig. 5, the inner ends of the legs of the sight do not meet. In practice the distance between the inner or bottom ends of the legs is very slight, and said bottom ends meet in a sharp edge. The ends of the legs of the sight which are directly adjacent the barrel, are designated as the inner ends of the legs. These legs may also be designated as sight members.

While the invention is not limited to any particular type of ammunition or to any particular type of gun or the like, the following is given as a single illustrative example, in connection with Fig. 5.

It is assumed that the improved sight takes the place of the conventional front sight of a gun. This gun may be of any type, including a rifle, a machine gun or the like. This gun shoots a .30.30-- grain cartridge. This example applies to several other types of cartridges which have approximately the same trajectory. This example, therefore, applies to the ordinary rifles which are used for hunting. It is also assumed that the target or object has a horizontal dimension of 1 foot and that the eye of the marksman will be held 2 feet behind the front sight. The distance between the eye of the marksman and the front sight may be varied within reasonable limits, without substantially lessening the accuracy of the device.

The gun is arbitrarily zeroed for the line A of Fig. 5, at a range of 50 yards. The line A corresponds to the substantially straight and horizontal outer or top-portions of the legs of the sight.

If this ammunition is used, the bullet has a drop' of 2 inches at a range of 100 yards, a drop of 6 inches at a range of 150 yards, a drop of 14 inches at a range of 200 yards, a drop of 25 inches at a range of 250 yards, and a drop of 40 inches at a range of 300 yards.

The invention can also be applied to a telescopic sight, in which case the lines which correspond to the members 2 are etched or otherwise indicated upon a transparent reticule. Therefore, when I refer to a front sight in a claim or claims, this includes a telescopic sight.

As previously stated, the curved legs .of the sight will theoretically never meet at their inner ends, as shown in the scale representation of Fig. 5, which is drawn to a scale which is ten times the actual scale of the device. In Figs. 1-4 inclusive, the parts are not drawn according to scale, as these figures are intended merely to illustrate the device generally. Likewise, in actual practice the sights are free from the horizontal lines AF, which are shown in Fig. 5. These lines AF of Fig. 5 are used merely to explain the theory and operation of the improved sight, when the gun is aimed at an object whose horizontal dimension is 1 foot, and when using a bullet which has the previouslystated trajectory. In Fig. 5, the respective legs of the sight are designated by the reference letters L and La. The respective lengths of the lines AF between the lines Land La in a device whlch is made according to Fig. 5, using ammunition which has the aforesaid trajectory, for shooting at a target which has a horizontal dimension of one foot, are as follows:

The respective vertical distances from the top line A to the other lines B--F are as follows:

Inch A to B 0.0167 A to C 0.0333 A to D 0.0583 A to E 0.0833 A to F 0.1111

In shooting at said object, the plane of the sight is held perpendicular to the axis of the barrel.

When the plane of the sight is perpendicular to the axis of the barrel, the lines A-F respectively correspond to ranges of 50 yards, 100 yards, 150 yards, 200 yards, 250 yards, 300 yards, when shooting at the aforesaid target, with a bullet which has the aforesaid trajectory.

The marksman aims the gun at the aforesaid object until its horizontal image has its ends coincident with the corresponding horizontal points of the legs of the sight. Under such conditions, if the horizontal image of said object is located on the horizontal line D, the range is 200 yards, and the gun has been automatically elevated to correspond to the aforesaid drop of 14.00 inches. The marksman need not calculate or estimate the range.

If the same ammunition is used, and the object has a horizontal dimension of 2 feet, for example, and the plane of the sight is normal to the axis of the bore 2, the marksman may 10- cate the image of the object horizontally until one-half of the horizontal dimension of the image is located between the legs of the sight, onequarter of the horizontal image is located at the left of the left-hand leg of the sight, and one-quarter of the horizontal dimension of the image is located to the right of the right-hand leg of the sight.

If the sight were dimensioned to shoot with the same ammunition at a target whose horizontal dimension was 2 feet, the length of line A, between its intersections with the legs of the sight, would be 0.400 inch, and the other horizontal dimensions would be doubled. The respective vertical distances between line A and lines B--F would remain the same, since the trajectory of the bullet would remain the same.

The above directions apply where it is desire to hit the center of the target.

The horizontal axis around which the sight turns, in the embodiment of Figs. 1 and 2, corresponds to the line A of Fig. 5. The eifect of turning the sight relative to the line A is to diminish the respective vertical distances between the top line A and the lower lines BF, and thus to vary the distance between the barrel and the inner ends of the legs of the sight. In this embodiment, the sight is adjusted so as to increase the distance between the barrel and the inner ends of the legs of the sight, in order to adjust the sight for flatter trajectories, or for smaller objects.

The top portions of the legs of the sight are substantially horizontal and the sight tilts or turns around an axis which is substantially coincident with the common axis of said horizontal top portions. Said axis of tilt coincides substantially with the line A. As previously stated, when the plane of the sight is perpendicular to the axis of the bore 2 of the rifle, said sight is designed for an object whose horizontal dimension is 1 foot. Strictly speaking, the sight is not in a single plane, but its legs or sight members are equivalent to two curved lines which are in the same plane. If the sight is turned around said axis until the line E is at the same level as the level which is occupied by the line D in Fig. 5, then the horizontal distance between the legs of the sight at this new upper level of the line E is 0.040 inch, instead of being 0.050 inch. Therefore, if the object or target has a horizontal dimension of 0.80 foot, instead of 1 foot, and the distance of the object or target is 200 yards, the ends of the image of the target will coincide with the points of intersection between the line E and the legs of the target, at this new upper position of the line E. Therefore, if the new target or object has a horizontal dimension of 0.80 foot and the range is 200 yards, the elevation of the rifle will be correctly adjusted when the ends of the horizontal image of the object coincide with the points at which the line E (in its new and elevated position) intersect with the legs of the target. This adjustment automatically corresponds to the various ranges. j Therefore, if the sight corresponds to an object which has a relatively large horizontal dimension, the sight can be readily adjusted by tilting its plane relative to the axis of the bore of the rifle, so as to correspond to objects which have smaller horizontal dimensions. The scale 9 is calibrated so that the 33. GEOMETRICAL INSTRUMENTS.

foot, etc.

tilting of the plane of the sight from its normal position corresponds to the respective target widths.

In the embodiment of Figs. 3 and 4, the sight is turned around an axis which, for convenience, may be designated as a vertical axis, since said axis is vertical when the axis of the bore 2 is horizontal. By turning the sight around said vertical axis, the lengths of the projections on a plane which is perpendicular to the axis of bore 2, of the portions of the parts of lines A-F which are located between the legs of the sight, are diminished. For example, the sight may be turned around said vertical axis until the length of the projection of the intersecting part of the line D on said perpendicular plane is 0.040 inch, instead of being 0.050 inch. Therefore, if the object or target has a horizontal dimension of 0.80 foot instead of having a horizontal dimension of 1 foot, and the range is 200 yards, the ends of the horizontal image of said object (having a horizontal dimension of 0.80 foot) will then coincide with the points of intersection between the line D and the legs of the target. Therefore, the embodiment of Figs. 3 and 4 can also be used by adjusting the sight, in order to correspond to objects whose horizontal dimensions are smaller than the horizontal dimension of the object for which the sight is designed, when the plane of said sight is perpendicular to the axis of the bore 2.

For example, in the embodiment of Figs. 3 and 4, when the plane of the sight is perpendicular to the axis of the bore 2, the sight may be shaped and dimensioned so as to correspond to an object whose horizontal dimension is 0.80 foot. By turning the head 8a, of the sight, it can be adjusted so as to correspond to objects having respective horizontal dimensions of 0.70 foot, 0.60 The scale in Figs. 3 and 4 is located on the turnable head 8a of the sight, and the index is located on the frame 4.

In addition to adjusting the sight on a rifle or gun whose ammunition has a predetermined trajectory, for targets which have different horizontal dimensions, the improved adjustable sight can beadjusted for use on different guns or rifles whose ammunition has different respective trajectories, for shooting at a target of the same horizontal dimension.

For example, assume that it is desired to fire at a target whose horizontal dimension is one foot. with ammunition whose trajectory is flatter than the trajectory previously mentioned.

At a range of 200 yards, for example, the elevation of the gun or rifle must then be decreased, in order to compensate for said flatter trajectory, since the drop is less than in the example previously given. The sight is then turned around its horizontal axis until the vertical distance between line A and line D is diminished, in order to correspond to said flattened trajectory. The distance between the barrel and the inner end of the legs of the sight is thus increased.

The legs of the sight can be mounted on a horizontal shaft at the line A, and said shaft can be mounted to turn around a vertical axis, in order to combine both said adjustments. Both embodiments are based upon the same essential principle. Each embodiment may be considered in connection with a reference plane which is perpendicular to the axis of the barrel. This reference plane may be considered as having a number of predetermined reference lines which are parallel to each other and which are perpendicular to respective lines which are parallel to the axis of the barrel. These reference lines are the imaginary lines A-F. These reference lines are taken at predetermined distances from the axis of the barrel, along a line which is perpendicular to the axis of the barrel, and in said reference plane. The respective distances between the sight members, measured along said respective reference lines, correspond to the respective correct elevations for a series of ranges of a target. In each embodiment, the sight is adjustable so that it is possible to vary the distances between said sight members, measured along said predetermined reference lines.

The horizontal dimension of the target may be designated as a guide dimension. Any guide dimension other than the horizontal dimension may be used. The legs of the sight may be designated as sight members. The sight members are inclined to each other in fixed relation, when the sight is being used.

I have shown preferred embodiments of my invention. but it is clear that numerous changes and omissions could be made without departing from its spirit.

I claim:

1. For use on the barrel of a rifle or the like, a front sight which has inwardly extending sight members which are inclined towards each other in fixed relation, the respective distances between said sight members which are taken parallel to and along respective predetermined reference lines being different, said predetermined reference lines being parallel to each other and being located in a reference plane which is perpendicular to the axis of the barrel and being spaced from each other and from the axis of the barrel at predetermined distances along a line which is located in said plane and which is perpendicular to said axis of the barrel, each reference line being perpendicular to a line which is parallel to the axis of the barrel, said respective distances which are taken along said predetermined reference lines corresponding to the respective correct elevations-for a series of ranges of a target which has a predetermined guide dimension, a support mounting said front sight on said barrel, said front sight being tiltable relative to said support around a predetermined axis of tilt, said respective distances which are taken parallel to and along said predetermined reference lines being apparently changed when said sight is tilted around said predetermined axis of tilt, said changed distances which are taken parallel to and along said respective reference lines corresponding to the respective correct elevations of a series of ranges of a target which has a predetermined guide dimension which is different from the previously mentioned guide dimension.

2. For use on the barrel of a rifle or the like, a front sight which has inwardly extending sight members which are inclined towards each other in fixed relation, the respective distances between said sight members which are taken parallel to and along respective predetermined reference lines being different, said predetermined reference lines being parallel to each other and being located in a reference plane which is perpendicular to the axis of the barrel and being spaced from each other and from the axis of the barrel at predetermined distances along a line which is located in said plane and which is perpendicular to said axis of the barrel, each reference line being perpendicular to a line which is parallel to the axis of the barrel, said respective Mini v. l

distances which are taken along said predetermined reference lines corresponding to the respective correct elevations for a series of ranges of a target which has a predetermined guide dimension, a support mounting said front sight on said barrel, said front sight being adjustable relative to said support so that the apparent distance between the inner ends of said sight members and the axis of the barrel can be varied, and said respective distances which are taken parallel and along said respective references lines can be changed, said changed respective differences taken parallel to and along said respective reference lines corresponding to the respective correct elevations of a series of ranges of a target which has a predetermined guide dimension which is different from the previously mentioned guide dimension.

3. For use on the barrel of a rifle or the like, a front sight which has inwardly extending sight members which are inclined towards each other in fixed relation, the horizontal distances between said sight members being spaced from the bore of the rifle in amounts corresponding to the respective correct elevations for a series of ranges of a target which has a predetermined guide dimension adapted to be optically spanned by one distance between said members as the rifle is aimed, a support mounting said front sight on said barrel, said sight being tiltable relative to said support around an axis of tilting which is substantially horizontal and normal to the axis of the barrel when the axis of the barrel is horizontal, said axis of tilting being substantially perpendicular to the axis of the barrel.

4. For use on the barrel of a rifle or the like, a front sight which has downwardly extending sight members which are inclined towards each other in fixed relation, the horizontal distances between said sight members being spaced from the bore of the rifle in amounts corresponding to the respective correct elevations for a series of respective ranges of a target which has a predetermined guide dimension, a support mounting said sight on said barrel, said front sight being adjustably connected to said support, said sight members being substantially parallel to a predetermined plane, said sight members being adjustable relative to said support to vary the angle between said plane and the axis of the bore of the rifle.

LEO H. BROWN.

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